Can anybody explain the line part in code. What is the meaning of Corner1 (2) means?

line([corner1(2);corner2(2);corner3(2);corner4(2);corner1(2)],[corner1(1);corner2(1);corner3(1);corner4(1);corner1(1)],'color','blue','LineWidth',2);

Answer 1

[KSSV]

Read about function line

https://in.mathworks.com/help/matlab/ref/line.html

This is used to plot a line, it needs x and y coordinates. In your code, the coordinates are defined in corners...you are giving input to the line.